To each his own.
This is really the important statement. Phones are in a state now that I think we can actually have 3 viable OSes in the market. I know families where the dad has a BB, the mom an iPhone, and a child an Android (or Sidekick back in the day), and no one cares. It's not like PCs.
When I go and look at a WebOS device or WP7 I'm not worried about the fact that they have small market share. For the most part it doesn't matter that much to me as a consumer. Sure WP7 only has 20,000 apps. But unless you're Robert Scoble, you'll be more than happy (and if you're Robert Scoble, apps don't even count until you hit 500k).
It's a very different world, and I think we'll see things evolve quite differently.